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We have conducted the study of ultrastructural changes of wall and cytoplasm of Plantago lanceolata (English plantain) pollen grains during the first 10 min of hydration and activation processes, prior to germination, and localisation of Pla l 1, the major allergen of these pollen grains with immunocytochemical methods. The samples were fixed using conventional and freezing protocols for transmission electron microscopy. During the activation process, the intine is thickened in the apertural region and cytoplasm undergoes changes in the number of lipid bodies, amyloplasts, vacuoles and ribosomes. Also, we observed an association between lipid bodies, cisternae of rough endoplasmic reticulum, dictyosomes and vacuoles. An increase in the presence of allergenic particles (Pla l 1) in the exine, intine and the cytoplasm in activated pollen grains was detected, whereas this presence is not significant in mature pollen grains. The increase in the production and release of this allergen when pollen grains are activated suggest that Pla l 1 has an important role in pollen–stigma recognition and in the subsequent development of the pollen tube. [ABSTRACT FROM AUTHOR]

Introduction. Exposure to airborne pollen from certain plants can cause allergic disease, but allergens can also be found in non-pollen-bearing fractions of ambient air. This may explain why the allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. Plantago pollen is an important cause of pollinosis in northern Mediterranean countries, but it is difficult to determine its incidence in allergies because Plantago pollen appears in the atmosphere at the same time as grass pollen. Objective. The study aimed to investigate the relationship between the atmospheric concentration of Pla I 1 aeroallergen and Plantago pollen, and its incidence in a population group. Materials and method. Pollen was sampled using a Hirst-type volumetric trap (Burkard™) and Burkard Cyclone sampler (Burkard™) for Pla I 1 allergen. Allergen was determined with a Pla I 1-specific ELISA. Serum-specific IgE levels to several plant allergens were measured with the EAST system. Results. The aerobiological dynamics of Plantago pollen grains and Pla I 1 did not follow the same trend, whereas the sum of Plantago with some other pollen types showed a more similar behaviour. Of the 118 subjects tested, sera from 52 contained IgE to Plantago pollen, but only 5 were monosensitized. Conclusions. The presence of Pla I 1 in the atmosphere depends not only on Plantago pollen but also on the pollen of other species from the Oleaceae family. Knowledge of the behaviour of allergen Pla I 1 in the atmosphere can help understand better asthma exacerbations associated with aeroallergens. [ABSTRACT FROM AUTHOR]

In order to survive periods of adverse cold climatic conditions, plant requirements are satisfied by means of physiological adaptations to prevent cells from freezing. Thus, the growth of woody plants in temperate regions slows down and they enter into a physiological state called dormancy. In order to identify the chilling and heat requirements to overcome the dormancy period of Cupressaceae pollen type in the south of Europe, we have carried out our study with aerobiological data from a 10-year (1996-2005) period in Ponferrada, León (Spain). For the chilling requirements the best result was with a threshold temperature of 7.1°C and an average of 927 CH. Calculation of heat requirements was carried out with maximum temperature, with 490 growth degree days (GDD) needed, with a threshold temperature of 0°C. We have used the 2002-2003, 2003-2004 and 2004-2005 periods in order to determine the real validity of the model. We have not used these years in developing the models. The dates predicted differ in only a few days from those observed: in 2002-2003 there was a difference of 11 days, in 2003-2004 predicted and observed dates were the same, but in 2004-2005 the difference obtained was of 43 days. [ABSTRACT FROM AUTHOR]